MDEV-18478 ANALYZE for statement should show selectivity of ICP, part#2

Part#2, variant 2: Make the printed r_ values in JSON output consistent.
After this patch, ANALYZE output has:

- r_index_rows (NEW) - Observed number of rows before ICP or Rowid Filtering
  checks. This is a per-scan average. like r_rows and "rows" are.

- r_rows (AS BEFORE) - Observed number of rows after ICP and Rowid Filtering.

- r_icp_filtered (NEW) - Observed selectivity of ICP condition.

- (AS BEFORE) observed selectivity of Rowid Filter is in
  $.rowid_filter.r_selectivity_pct

- r_total_filtered - Observed combined selectivity: fraction of rows left
  after applying ICP condition, Rowid Filter, and attached_condition.
  This is now comparable with "filtered" and is printed right after it.

- r_filtered (AS BEFORE) - Observed selectivity of "attached_condition".

Tabular ANALYZE output is not changed. Note that JSON's r_filtered and
r_rows have the same meanings as before and have the same meaning as in
tabular output.

mysql-test/main/analyze_engine_stats.result

@@ -40,8 +40,9 @@ X
  "pages_accessed": "REPLACED"
  },
  "filtered": 100,
- "r_filtered": 100,
- "attached_condition": "t1.pk < 120000"
+ "r_total_filtered": 100,
+ "attached_condition": "t1.pk < 120000",
+ "r_filtered": 100
  }
  }
  ]
@@ -70,13 +71,14 @@ X
  "access_type": "ALL",
  "rows": 10000,
  "r_rows": 10000,
- "r_filtered": 100,
+ "r_total_filtered": 100,
  "r_total_time_ms": "REPLACED",
  "r_engine_stats": {
  "pages_accessed": "REPLACED",
  "pages_updated": "REPLACED"
  },
- "attached_condition": "t1.pk < 120000"
+ "attached_condition": "t1.pk < 120000",
+ "r_filtered": 100
  }
  }
 }
@@ -103,13 +105,14 @@ X
  "access_type": "ALL",
  "rows": 10000,
  "r_rows": 10000,
- "r_filtered": 50,
+ "r_total_filtered": 50,
  "r_total_time_ms": "REPLACED",
  "r_engine_stats": {
  "pages_accessed": "REPLACED",
  "pages_updated": "REPLACED"
  },
- "attached_condition": "t1.pk MOD 2 = 1"
+ "attached_condition": "t1.pk MOD 2 = 1",
+ "r_filtered": 50
  }
  }
 }
@@ -155,6 +158,7 @@ ANALYZE
  "r_other_time_ms": "REPLACED",
  "r_engine_stats": REPLACED,
  "filtered": 100,
+ "r_total_filtered": 100,
  "r_filtered": 100
  }
  },
@@ -174,6 +178,7 @@ ANALYZE
  "r_table_time_ms": "REPLACED",
  "r_other_time_ms": "REPLACED",
  "filtered": 100,
+ "r_total_filtered": 100,
  "r_filtered": 100,
  "materialized": {
  "unique": 1,
@@ -193,6 +198,7 @@ ANALYZE
  "r_other_time_ms": "REPLACED",
  "r_engine_stats": REPLACED,
  "filtered": 100,
+ "r_total_filtered": 100,
  "r_filtered": 100
  }
  }